I've been looking at engineering a new turbo setup for an A-series based on a
modern and commonly available turbocharge that others could copy. The Rayjay
on my bugeye is fantastic, but no longer available.
After much research, I've discovered that ALL modern turbos are meant for
blow-through operation. The simple arrangement of an SU ahead of a turbo
won't work with a modern turbo. The seals will allow oil to be sucked through
the bearings when the throttle plate is closed. Much blue smoke, bad ju-ju.
To use a turbo in a carburetted blow-through arrangement is discussed in
Vizard's book and seems prohibitively difficult, so I'm dropping the project.
It seems the PO was even more clever than I ever knew, as he engineered the
Sprite with the only commonly available (at that time) turbo with carbon seals
that can work well in a suck-through application.
If I take this up again it will be after building a Megasquirt for a single
port/throttle body manifold for an A-series. Then the ducks will be in a row
for future turbocharging. Till then, it looks like I'm stuck with the only
turbocharged bugeye in town, looking for overpriced supercharged ones to
spank. Oh well.